The present apparatus relates to an aerial lift platform apparatus, and more particularly to the support system for control conduits which extend between the inner end of the boom and the aerial lift platform on the outer end of the boom.
Aerial lift platform apparatus are known in which there is provided an extensible boom, which may be positioned at different angles to the vertical, and which have a workman's basket or platform at the outer end of the boom, typically at the outer end of the fly section. On or adjacent the workman's platform there is provided a control console, provided with various control elements which may be manipulated by the workman to control such functions as boom angle, boom extension, the rotation of the boom on a vertical axis, and where the aerial lift platform apparatus is of the self-propelled type, there are also provided engine, steering and braking controls. Flexible control conduits have been provided, extending between the control console and the inner or rearward end of the boom, from which they extend to various controlled elements in known manner. These flexible control conduits may include hydraulic hoses and/or electrical cables.
In order to prevent the flexible control conduits from becoming entangled or snarled during extension and retraction of the boom, it has been known to utilize a self-supporting carrier track: see Grove U.S. Pat. Nos. 3,776,367 and Eitel et. al. 3,480,109. These known constructions, which have proven to be satisfactory, were utilized, however, only in connection with telescopic booms of three sections, and of a length sufficient to give a height of the floor of the workman's platform of approximately eighty feet above the ground. Where booms of greater lengths, and therefore greater platform height are required, there have been other systems utilized for supporting the control conduits. See, for example, Garnett U.S. Pat. No. 3,212,604.
The prior art has not disclosed the utilization of the facile self-supporting carrier track on booms of such great length so as to give a platform height of 110 feet. The utilization of a single carrier track, it has been discovered, would not be satisfactory.